Synthesis of gradient polymer by using polysiloxane‐based photoinitiator

This paper reported a polysiloxane‐based photoinitiator (184‐AC‐Si), which was synthesized basing on traditional photoinitiator 1‐hydroxy‐cyclohexyl phenyl ketene (184) and polysiloxane. Its structure was confirmed by Hydrogen‐1 nuclear magnetic resonance (¹H NMR), real‐time infrared spectroscopy and gel permeation chromatography (GPC). Ultraviolet (UV) absorption spectra of 184‐AC‐Si showed a red‐shifted maximum absorption compared with 184. The kinetics of photopolymerization was studied by real‐time infrared spectroscopy. More importantly, because of the polysiloxane‐based photoinitiator had good ability to float up, which could be proved by X‐ray photoelectron spectroscopy, mapping energy dispersive spectroscopy, UV absorption, and GPC measurements, a convenient and simple method for preparing gradient polymer initiated by 184‐AC‐Si was successfully developed. Copyright © 2011 John Wiley & Sons, Ltd.